Aminomethyl Group-Modification of Chloromethylated Polystyrene Microspheres and Preparation of Schiff Base-Type Chelating Resin Microspheres

Abstract

A Schiff base-type chelating resin(SACPS) was prepared by two polymeric reaction steps using chloromethylated polystyrene microspheres(CMCPS) as starting material.Firstly,in the presence of catalyst KI,the Delepine reaction between the chloromethyl groups and hexamethylene tetramine(HMTA) was carried out to yield aminomethyl(AM) group-modified CPS microspheres(AMCPS).Then the reaction between AMCPS microspheres and salicylaldehyde(SA) resulted the formation of Schiff base-type chelating resin(SACPS).The aminomethyl group-modification of CMCPS was systematically investigated,and the effects of main factors on the Delepine reaction were examined.The experimental results showed that KI has a strong catalytic activity toward the Delepine reaction.Higher solvent polarity favored the fracture of C—Cl bond of the benzyl chloride group,and could accelerate the Delepine reaction.The increase of the reaction temperature is also advantageous to the reaction.DMSO is a suitable solvent and 80 ℃ is an appropriate temperature.The prepared SACPS resin possesses strong chelating ability for Cu2+.